Alcohol dehydrogenase in non-aqueous media using high-pressure technologies: reaction set-up and deactivation determination

BACKGROUND: The demand for enantiomerically pure molecules is growing continuously and biocatalysis is a powerful technique for their production. In this work, the catalyst was an enzyme combined with its coenzyme, NADP. High pressure technology, a second clean technology, was applied as well. Dense gases are promising solvents for biocatalysis. They have been investigated extensively as reaction media for lipase-catalysed reactions, but seldom for reactions, catalysed with alcohol dehydrogenases, as in this work. RESULT: The production of optically pure R-1-phenylethanol from acetophenone was investigated. The NADP-dependent alcohol dehydrogenase from Lactobacillus brevis (LBADH) was used as a catalyst. The hydrogenation was performed with isopropanol as a co-substrate in different conditions: dense propane with LBADH and NADP co-immobilized on glass beads and in the biphasic system water/dense propane. The obtained R-1-phenylethanol was enantiopure. The conversions were up to 90%. Deactivation of LBADH was also measured in these media. CONCLUSION: Protocols were successfully developed for the testing of alcohol dehydrogenase activity in dense gases. Enantioselectivity of LBADH is excellent in those media but it deactivated quickly. An LBADH-catalysed reaction was performed in a dense gas for the first time. (C) 2010 Society of Chemical Industry